Method and apparatus for implementing enablement state decision for energy consuming load based on demand and duty cycle of load

ABSTRACT

A method for managing an energy consuming load in a group of energy consuming loads and a method for managing the group of energy consuming loads. The method includes generating sets of load state data from the loads, making enablement state decisions for one or more loads independently of the other loads using the sets of load state data, and implementing the enablement state decisions. An apparatus for managing an energy consuming load in a group of energy consuming loads, including a transmitter for transmitting a set of load state data generated from the load, a receiver for receiving sets of load state data from other loads, a processor for processing the sets of load state data to make an enablement state decision for the load, and a controller for implementing the enablement state decision.

TECHNICAL FIELD

A method and apparatus for managing a group of energy consuming loadsand for managing an energy consuming load in a group of energy consumingloads.

BACKGROUND OF THE INVENTION

Energy is provided by suppliers to consumers in many forms and from manysources. Typical forms and sources of energy include electricity,natural gas, coal, oil, atomic energy etc.

Escalating energy costs and infrastructure costs have made managing bothenergy supply and energy consumption a critical issue which is importantto both suppliers of energy and consumers of energy.

From a supplier's perspective, both the energy consumption of consumersand the energy demand by consumers must be accommodated by the energyinfrastructure. Energy consumption is the total amount of energy whichis consumed over a time period, while energy demand is the rate at whichthe energy is consumed. Peak energy demand is the maximum rate at whichenergy is consumed. Energy consumption over a time period is a functionof the energy demand over the time period.

An energy infrastructure must be capable of supplying the total amountof energy that is required by consumers and must also be capable ofsatisfying the peak demand for energy which is imposed upon the energyinfrastructure.

In a typical energy supply system, the energy demand fluctuates overminutes, hours, days, weeks, months etc. Since energy consumption is afunction of energy demand, an energy supply system in which energyconsumption is relatively low may exhibit a relatively high peak energydemand if the energy demand fluctuates greatly, while an energy supplysystem in which energy consumption is relatively high may exhibit arelatively low peak energy demand if the energy demand fluctuatesminimally.

An efficient energy supply system is a system in which the energy demandfluctuates minimally, since the energy infrastructure must be designedto satisfy the peak demand. As the fluctuation of the energy demanddecreases, the peak energy demand for the energy supply systemapproaches the average energy demand on the energy supply system, whichis the lowest peak energy demand which can be attained for the energysupply system. The energy demand on an energy supply system is thereforepreferably managed so that the peak energy demand is minimized.

An energy supply system may provide energy to any number of consumers.The energy demand on an energy supply system may be managed on one levelby managing the energy demands of the consumers who are connected withthe energy supply system. The energy demand on an energy supply systemmay also be managed on a second level by managing the energy demands ofthe individual energy consuming loads which are connected with theenergy supply system through the consumers.

In either case, managing the energy demand on the energy supply systeminvolves distributing the energy demands of consumers and/or loads inorder to avoid a large peak energy demand on the energy supply system.The distribution of energy demands may be accomplished by adjusting thetimes at which “discretionary loads” consume energy from the energysupply system.

A discretionary load is an energy consuming load which is not requiredto be operated rigidly according to a fixed schedule, or rigidlyaccording to a fixed set of constraints such as temperature, humidity,etc., with the result that the time or times at which it consumes energycan be adjusted. Typically, a discretionary load has a duty cycle whichis less than 100 percent, where duty cycle is defined as the percentageof time that the load must operate in order to satisfy its assignedobjectives.

For example, if a heater must operate 50 percent of the time in order tomaintain a desired temperature within a space, the duty cycle for theheater is 50 percent. If the heater isn't required to operate rigidlyaccording to a fixed schedule, or rigidly within a fixed set ofconstraints while satisfying its duty cycle, the heater is also adiscretionary load.

Some energy suppliers provide incentives or disincentives to consumersto assist in managing the energy demand on the energy supply system.

For example, in the case of an electrical system, suppliers may includein their billing both a “consumption charge” and a “peak demand charge”,particularly in the case of commercial, institutional and industrialconsumers. The consumption charge is based upon the total amount ofelectricity consumed in the billing period (typically measured inkilowatt-hours, or “kWh”). The peak demand charge is often based uponthe greatest amount of electricity used during a sustained fifteenminute period (typically measured in kilowatts, or “kW”).

The consumption charge compensates the supplier for the electricitywhich is consumed by a consumer. The peak demand charge compensates thesupplier for the energy infrastructure which must be provided in orderto accommodate the peak demand on the electrical system.

It may therefore be in the financial interest of a consumer to manageits energy demand in order to minimize the peak energy demand which isimposed by the consumer on the energy supply system.

Systems have been contemplated for managing energy consumption and/orenergy demand.

U.S. Pat. No. 4,023,043 (Stevenson) describes a system and method forlowering electrical energy peak demand while minimizing servicedisruption, which includes a centralized transmitter means whichgenerates and transmits signals which disconnect interruptible loads inresponse to the approach of an excessive demand peak, and whichgenerates and transmits signals to reconnect the interruptible loadsthereafter, based upon characteristic projected energy consumptionprofiles predicted from past historical records.

U.S. Pat. No. 4,264,960 (Gurr) describes a system for permitting anelectric power utility to control the distribution of its power alongits power lines from a substation to a plurality of customer loads. Thesystem provides direct control of customer loads with a view towardfacilitating enablement of a load management philosophy which includespeak shaving and load deferral. The system includes a master controlstation which generates master control signals which are converted topulse code signals by a substation injection unit, wherein the pulsecode signals provide instructions for connecting or disconnectingcustomer loads from the power lines.

U.S. Pat. No. 4,686,630 (Marsland et al) describes a load managementcontrol system and method which communicates load shedding informationfrom a central station controller to a substation controller. Thesubstation controller then sends encoded step voltage signals down apower distribution line to a load control receiver, which decodes thesignals and controls loads which are associated with the load controlreceiver.

U.S. Pat. No. 5,244,146 (Jefferson et al) describes an apparatus andmethod for controlling the operation of an HVAC system in order toconserve energy. The method involves initiating a “fuel-on interval” inwhich fuel is consumed by the HVAC system, terminating the fuel-oninterval and initiating a “fuel-off interval” in which fuel is notconsumed by the HVAC system. Heat is distributed through the HVAC systemduring a “delivery interval” which is initiated during the fuel-offinterval. The apparatus includes a thermostat which initiates andterminates the fuel-on interval, the fuel-off interval, and the deliveryinterval.

European Patent Specification No. EP 0 814 393 B1 (Eriksson et al)describes a system for controlling and supervising electricalcomponents/devices connected to an electrical network via a publicinformation network, wherein the system is accessible from any terminalconnected to the public information network.

U.S. Patent Application Publication No. US 2002/0162032 A1 (Gundersen etal) describes a system, method and computer program for providingautomated load management in an electrical power generation,transmission and distribution network by means of control signals in acommunications protocol which is compatible with the world wide web andother Internet technologies. The method involves the carrying out by aload point device of load shaving or load shedding actions affectingloads, which actions are based upon decisions calculated using referenceinformation for the loads which are stored in the device.

U.S. Patent Application Publication No. US 2005/0192713 A1 (Weik et al)describes a method of managing energy consumption by a group of energyconsuming devices. The energy consuming devices exchange messagesaccording to an energy management control protocol via a communicationmedia. The energy management control protocol includes an energy bookingmessage type for announcing future energy consumption, an energyreduction indication type for announcing possible reduction of energyconsumption, and a granting message type for granting an energy bookingmessage and/or an energy reduction indication. The energy consumingdevices negotiate their energy consumption by means of the messagesexchanged according to the energy management control protocol andcontrol their energy consumption according to the result of thisnegotiation. The group of energy consuming devices are described asconstituting a self-organizing network which negotiate with each otheraccording to scheduling rules without a central energy managementcontrol device to provide scheduling functionalities.

Self-organization as referred to in Weik et al is somewhat related tomulti-agent systems and emergence theory. Self organization is a processin which the internal organization of a system increases in complexitywithout guidance or management from an outside source. A multi-agentsystem is a system composed of a group of agents which interactaccording to defined rules to achieve functionality that would bedifficult or impossible to achieve by the agents acting individually.Emergence is the process of complex pattern formation from simple rules.

Emergence is sometimes described with reference to “swarm” or “hive”behaviour whereby a group of simple devices, acting in a swarm, canexhibit behaviour which is seemingly more intelligent and complex thanthe simple behaviour programmed into the individual devices.

Both multi-agent systems and emergence theory have been proposed for usein controlling complex environments.

Brazier, Frances M. T., Comelissen, Frank, Gustavsson, Rune, Jonker,Catholijn M., Lindeberg, Olle, Polak, Bianca and Treur, Jan, “AMulti-Agent System Performing One-To-Many Negotiation for Load Balancingof Electricity Use”, Electronic Commerce Research And Applications, 1(2002) 208-224 describes a prototype system which involves interactionbetween a Utility Agent (i.e., a utility supplier) and a group ofCustomer Agents (i.e., consumers) for the purpose of negotiating for thesupply of electricity from the Utility Agent to the Customer Agents.

Van Dyke Parunak, H., “An Emergent Approach to Systems of PhysicalAgents”, J. Expt. Theor. Artif. Intell. 9(1997)211-213 describes anapplication of emergence theory in which “agents” (such as parts andequipment) interact with each other in order to permit an overall shopschedule to emerge dynamically from the interaction, instead of beingimposed top-down from a central control.

Rosario, L. C., “Multi-Agent Load Power Segregation for ElectricVehicles”, 2005 IEEE Vehicle Power and Propulsion Conference (IEEE Cat.No. 05EX1117C), 2006, p 6 pp. describes the prioritization of activationof agents, wherein the agents are comprised of non-propulsion loadswhich have been segregated into multi-priority, multi-time constantelectrical burdens which may be imposed on an onboard energy storagesystem in an electric vehicle. The prioritization is performed using analgorithm which ensures the availability of the propulsion load demandby arbitrating the activation of the non-propulsion agents based uponassigned priority levels. This paper is described as providing aninitial step toward ongoing investigations into agent based power andenergy management schemes.

Valckenaers, P. “On the Design of Emergent Systems: An Investigation ofIntegration and Interoperability Issues”, Engineering Applications ofArtificial Intelligence, v. 16, n. 4, June 2003, p. 377-93 discussesdesign principles for the design of components for emergent systems,based upon experience gained during the development of researchprototypes for multiagent manufacturing control systems.

Ward, J., “Sensor Networks for Agent Based Distributed EnergyResources”, The Second IEEE Workshop on Embedded Networked Sensors (IEEECat. No. 05EX1105), 2005, p. 159-60 describes the development of agentsfor the control of distributed energy resources (DERs) in an electricitynetwork, which resources include both generators and loads. The agentsmay be used to allow collaboration amongst DERs in order to generate anaggregated response by the DERs to support the electricity network attimes of peak demand.

Fischer, K., “Specialised Agent Applications”, Multi-Agent Systems andApplications, 9^(th) ECCAI Advanced Course, ACAI 2001 and Agent Link's3^(rd) European Agent Systems Summer Scholl, EASSS 2001, SelectedTutorial Papers (Lecture Notes in Computer Science Vol. 2086), 2001, p.365-82 provides an overview of multi-agent system applications, focusingon the application of multi-agent systems in the context of supply chainmanagement in virtual enterprises.

There remains a need for a method and/or system for managing a group ofenergy consuming loads and/or an energy consuming load in the group ofenergy consuming loads which is relatively simple, which does notrequire negotiation amongst the loads, and which does not requirecentralized control of the loads.

There remains a need for such a method and/or system for use in managingthe energy demands of the loads and the collective energy demand of thegroup of loads with the goal of controlling the peak energy demand whichis exhibited by the group of loads.

There remains a need for such a method and/or system in which each ofthe loads is independently controlled using relatively simple ruleswhich are applicable to each of the loads.

SUMMARY OF THE INVENTION

The present invention includes a method for managing a group of energyconsuming loads comprising a plurality of loads, a method for managingan energy consuming load in a group of energy consuming loads, anapparatus for managing an energy consuming load in a group of energyconsuming loads, a computer readable medium for providing computerreadable instructions for managing an energy consuming load in a groupof energy consuming loads, an apparatus for receiving and processing thecomputer readable instructions in order to manage an energy consumingload in a group of energy consuming loads, a system of managed energyconsuming loads, and a system for managing an energy consuming load in agroup of energy consuming loads.

The invention is preferably directed at managing the energy demands ofenergy consuming loads and the collective energy demand of a group ofenergy consuming loads with the goal of controlling the peak energydemand of a group of energy consuming loads.

The method of the invention is comprised of making a decision relatingto the management of an energy consuming load in a group of energyconsuming loads, which decision is made independently of the otherenergy consuming loads without negotiating with the other loads, butwhich is made using information about the other loads. The method of theinvention may also be comprised of making decisions relating to themanagement of a group of energy consuming loads, wherein a separatedecision is made for each load and wherein the decisions are madeindependently of each other without negotiation amongst the loads, butusing information about the loads which is shared amongst the loads.

The apparatus of the invention may include structures and/or deviceswhich facilitate sharing of information amongst a group of energyconsuming loads, making a decision relating to the management of one ofthe loads using the shared information, and implementing the decision.

The apparatus of the invention may also include a processor whichfacilitates generating information about an energy consuming load in agroup of energy consuming loads, compiling information about the groupof energy consuming loads and making a decision relating to themanagement of the load using the compiled information. The computerreadable medium of the invention may provide computer readableinstructions for directing the processor.

In a first method aspect, the invention is a method for managing a groupof energy consuming loads comprising a plurality of loads, the methodcomprising:

-   -   (a) generating a set of load state data from each of the loads        in the group of loads;    -   (b) making an enablement state decision for each of the loads        using the sets of load state data from the loads, wherein each        of the enablement state decisions reflects an enablement state        of a corresponding load in the group of loads, wherein the        enablement state is either a load enabled state or a load        disabled state, and wherein each of the enablement state        decisions is made independently of the enablement state        decisions for the loads other than the corresponding load; and    -   (c) implementing the enablement state decisions.

In a second method aspect, the invention is a method for managing anenergy consuming load in a group of energy consuming loads comprisingthe load and a plurality of other loads, the method comprising:

-   -   (a) generating a set of load state data from the load;    -   (b) compiling the set of load state data generated from the load        with sets of load state data generated from the other loads;    -   (c) making an enablement state decision for the load using the        compiled sets of load state data, wherein the enablement state        decision reflects an enablement state of the load, wherein the        enablement state is either a load enabled state or a load        disabled state, and wherein the enablement state decision is        made independently of the other loads; and    -   (d) implementing the enablement state decision for the load.

In a first apparatus aspect, the invention is an apparatus for managingan energy consuming load in a group of energy consuming loads comprisingthe load and a plurality of other loads, the apparatus comprising:

-   -   (a) a transmitter configured to transmit a set of load state        data generated from the load;    -   (b) a receiver configured to receive sets of load state data        generated from the other loads;    -   (c) a processor configured to generate the set of load state        data from the load, to compile the set of load state data from        the load with the sets of load state data from the other loads,        and to process the compiled sets of load state data in order to        make an enablement state decision for the load, wherein the        enablement state decision reflects an enablement state of the        load, wherein the enablement state is either a load enabled        state or a load disabled state, and wherein the enablement state        decision is made independently of the other loads; and    -   (d) a controller for implementing the enablement state decision.

In a second apparatus aspect, the invention is an apparatus for makingan enablement state decision reflecting an enablement state of an energyconsuming load in a group of energy consuming loads comprising the loadand a plurality of other loads, wherein the enablement state is either aload enabled state or a load disabled state, the apparatus comprising aprocessor programmed to:

-   -   (a) generate a set of load state data from the load;    -   (b) compile the set of load state data from the load with sets        of load state data from the other loads; and    -   (c) process the compiled sets of load state data in order to        make the enablement state decision independently of the other        loads.

In a further aspect, the invention is a computer readable medium forproviding computer readable instructions for directing a processor tomake an enablement state decision reflecting an enablement state of anenergy consuming load in a group of energy consuming loads comprisingthe load and a plurality of other loads, wherein the enablement state iseither a load enabled state or a load disabled state, the instructionscomprising:

-   -   (a) generating a set of load state data from the load;    -   (b) compiling the set of load state data from the load with sets        of load state data from the other loads; and    -   (c) processing the compiled sets of load state data in order to        make the enablement state decision independently of the other        loads.

The invention is used to manage the enablement state of one or moreenergy consuming loads. The enablement state of the energy consumingloads is either a load enabled state or a load disabled state.

A load enabled state may be a state where the load is actually operating(i.e., “running”). Alternatively, a load enabled state may be a statewhere the load is capable of operating, even if it is not actuallyoperating. Preferably, a load enabled state is a state where the load iscapable of operating, even if it is not actually operating. In preferredembodiments, a load enabled state is achieved either by providing anenabled control line circuit so that control signals can be transmittedto the load or by providing an enabled energization circuit so thatenergy is available to the load.

Similarly, a load disabled state may be a state where the load is notoperating, or may be a state where the load is not capable of operating.Preferably, a load disabled state is a state where the load is notcapable of operating. In preferred embodiments a load disabled state isachieved either by providing a disabled control line so that controlsignals cannot be transmitted to the load or by providing disabledenergization source so that energy is not available to the load.

The energy consuming loads may consume any form of energy, eitherdirectly or indirectly. For example, the energy consuming loads maydirectly consume natural gas, propane or electricity, and may indirectlyconsume coal, oil, atomic energy or hydroelectric energy. In preferredembodiments the energy consuming loads are electrical loads whichdirectly consume electricity which is generated from other sources ofenergy.

The invention may be used to manage the state of the loads for anypurpose. For example, the purpose of managing the state of the loads maybe to reduce energy consumption, to provide for an energy consumptionschedule, to reduce energy demand or to provide for an energy demandschedule. In preferred embodiments the purpose of managing the state ofthe loads is to control the peak energy demand (i.e., peak electricitydemand) of the group of loads.

The energy consuming loads may be comprised of any type of load whichconsumes the form of energy which is of interest in the practice of theinvention. For example, where the form of energy is natural gas orpropane, the energy consuming loads may be comprised of heaters,furnaces, ranges etc. or any other type of device or apparatus whichconsumes natural gas or propane, and where the form of energy iselectricity, the energy consuming loads may be comprised of any type ofdevice or apparatus which consumes electricity, including but notlimited to heaters, air conditioners, coolers, refrigerators, freezers,fans, lights, appliances, computing devices etc.

The energy consuming loads may consume more than one form of energy. Forexample, a furnace may consume natural gas or propane in order togenerate heat, but may also consume electricity to power a fanassociated with the furnace. Where an energy consuming load consumesmore than one form of energy, the form of energy of interest may be oneor more of the forms of energy which are consumed by the load.

A duty cycle is the percentage of time that a load must operate in orderto satisfy its assigned objectives.

A duty cycle may be a natural duty cycle which defines the percentage oftime that the load must operate within its environment in order toprovide a particular result. For example, having regard to theenvironment in which a heater is installed, the heater may be requiredto operate 50 percent of the time in order to maintain the temperatureof a space within a desired range. In such circumstances, the naturalduty cycle of the heater could be described as being 50 percent.

A duty cycle may also be an assigned duty cycle which may be less thanor greater than the natural duty cycle of the load. An assigned dutycycle may, for example, be assigned to be less than the natural dutycycle in order to reduce energy consumption, and may be assigned to begreater than the natural duty cycle in order to provide increasedassurance that the load will satisfy its assigned objectives.

In the practice of the invention, the duty cycle for each of the loadsmay be its natural duty cycle or may be an assigned duty cycle. The dutycycles for the loads may also be variable, either due to changes in thenatural duty cycles of the loads or due to changes in the assigned dutycycles of the loads.

The energy consuming loads may be comprised of non-discretionary loadsand/or discretionary loads. A non-discretionary load is a load whichmust always be enabled, which must be enabled rigidly according to aschedule, which must be enabled rigidly according to a fixed set ofconstraints such as temperature, humidity etc., or which must always beavailable to be enabled when called upon.

A discretionary load is a load for which there is some flexibility inoperating within a schedule or within a set of constraints, as long asthe load is capable of achieving its duty cycle. For example, if aheater is set normally to turn on when a temperature within a space is20 degrees Celsius, and the turning on of the heater may be delayed sothat the heater turns on when the temperature within the space issomewhat less than 20 degrees Celsius, the load may be described as adiscretionary load.

A non-discretionary load may also be a load which is in a monitoringmode. In monitoring mode, the load is permitted to operate according toits duty cycle without intervention from the invention. As a result, inmonitoring mode, an otherwise discretionary load may be considered to bea non-discretionary load.

Each enablement state decision is made using load state data from theloads in the group of energy consuming loads. Preferably a set of loadstate data is generated for each of the loads. Preferably the enablementstate decision is made using sets of load state data from all of theloads. An enablement state decision may, however, be made using sets ofload state data from fewer than all of the loads if one or more sets ofload state data are unavailable, incomplete or unreliable.

Each set of load state data is comprised of information about acorresponding load. The information may be comprised of identifyinginformation, operational information or any other information which mayassist in making the enablement state decision for any of the loads.

Non-limiting examples of identifying information include information foridentifying the load and/or information for identifying the time towhich the load state data relates. Non-limiting examples of operationalinformation include information relating directly or indirectly to theduty cycle of the load, the energy demand of the load, the extent towhich the duty cycle has been satisfied by the load, and/or the extentto which the load contributes to a target system equilibrium of thegroup of loads.

The purpose of the sets of load state data is to provide informationabout the loads, which information is used to make the enablement statedecisions.

In preferred embodiments, each set of load state data is comprised of aload identifying indication for identifying the load, a time indicationfor identifying the time to which the load state data relates, an energydemand indication relating to the energy demand of the load, anenablement need indication relating to the extent to which the dutycycle of the load has been satisfied by the load, and a duty cycleindication relating directly or indirectly to the duty cycle of theload.

In particular preferred embodiments, the duty cycle indication is usedto determine the extent to which the load contributes to a target systemequilibrium for the group of loads. As a result the duty cycleindication may relate directly to the duty cycle of the load so that thecontribution of the load to the target system equilibrium can becalculated from the duty cycle indication of the load and the energydemand indication of the load. Alternatively, the duty cycle indicationmay relate indirectly to the duty cycle of the load so that the dutycycle indication is expressed as the contribution of the load to thetarget system equilibrium.

The sets of load state data from the loads are used to make anenablement state decision for each of the loads. Using the sets of loadstate data may be comprised of compiling the sets of load state datawhich are generated from the loads.

Preferably the enablement state decisions for each of the loads are madeusing the same sets of load state data. Preferably the enablement statedecisions for each of the loads are made by processing the sets of loadstate data using the same rules. However, each of the enablement statedecisions is made independently of the other loads. In other words, eachof the enablement state decisions is made without negotiation amongstthe loads and without regard to enablement state decisions affectingother loads.

Preferably at least one of the loads in the group of loads is comprisedof a discretionary load. Preferably at least one of the loads in thegroup of loads has a duty cycle which is less than 100 percent.Preferably at least one of the discretionary loads in the group of loadshas a duty cycle which is less than 100 percent.

Preferably the enablement state decisions are made with a goal ofachieving a target system equilibrium for the group of loads. Preferablythe target system equilibrium represents an energy demand for the groupof loads which approaches an average energy demand for the group ofloads. In preferred embodiments the target system equilibrium is equalto a sum for all of the loads in the group of loads of a product of theenergy demand of one of the loads and the duty cycle of the one of theloads. The contribution of a load to the target system equilibrium isthe product of the energy demand of the load and the duty cycle of theload.

Each of the loads in the group of loads may have an enablement need inorder to achieve its duty cycle. The enablement need may be based uponan amount of time in which the load has been in the load enabled state,upon an amount of time remaining for the load to achieve its duty cycle,and upon the duty cycle of the load. As a result, the enablement needdescribes the “urgency” of the need for the load to be placed in theload enabled state.

In preferred embodiments, the enablement state decisions for the loadsare constrained by the enablement needs of the loads. For example, theenablement state decision for a load which is at risk of not achievingits duty cycle may be more likely to indicate the load enabled statethan the enablement state decision for a load which is not at risk ofnot achieving its duty cycle. In such circumstances, each of the sets ofload state data is preferably comprised of an enablement need indicationof the enablement need of the corresponding load.

The enablement state decisions for the loads are particularlyconstrained by the enablement needs of non-discretionary loads. Wherenon-discretionary loads are included in the group of loads, theenablement needs of the non-discretionary loads may dictate theenablement state decisions for those loads and/or the implementation ofthe enablement state decisions for those loads.

For example, if a non-discretionary load must always be enabled or mustalways be enabled when called upon, the non-discretionary load may berequired always to be in the load enabled state. If a non-discretionaryload must be enabled rigidly according to a particular schedule, thenon-discretionary load may be required to be in the load enabled stateat particular times.

These results can be achieved by tailoring the sets of load state datafor non-discretionary loads to reflect the enablement needs of thenon-discretionary loads. For example, a non-discretionary load may beassigned a duty cycle of 100 percent in order to ensure that theenablement state decision provides that the load is always enabled.Alternatively, the enablement need of a non-discretionary load may beset so that the amount of time which is required in order for thenon-discretionary load to achieve its duty cycle is greater than orequal to the time remaining for the load to achieve its duty cycle.

Additionally or alternatively, these results may be achieved bytailoring the implementation of the enablement state decisions fornon-discretionary loads. For example, the implementation of anenablement state decision for a non-discretionary load may compriseplacing or maintaining the load in the load enabled state regardless ofthe enablement state decision. This approach effectively “overrides” anenablement state decision which would place the load in a load disabledstate.

In preferred embodiments, the enablement state decisions are alsoconstrained by the energy demands of the loads. For example, theenablement state decision for a load which will not cause the targetsystem equilibrium for the group of loads to be exceeded if the load isplaced in the load enabled state may be more likely to indicate the loadenabled state than the enablement state decision for a load which willcause the target system equilibrium to be exceeded if the load is placedin the load enabled state. In such circumstances, each of the sets ofload state data is preferably comprised of an energy demand indicationand a duty cycle indication.

Although the enablement state decisions are made independently for eachof the loads, the enablement state decisions are preferably made in adecision making sequence. The decision making sequence is preferablydependent upon the information contained in the sets of load state data.

As a first example, the decision making sequence may be dependent uponthe enablement needs of the loads, so that the enablement state decisionfor a load having a relatively higher enablement need is made before theenablement state decision for a load having a relatively lowerenablement need. In such circumstances, each of the sets of load statedata is preferably comprised of an enablement need indication of theenablement need of the corresponding load.

As a second example, each of the loads has an energy demand, whichenergy demand represents the rate at which the load will consume energywhen it is operating. Preferably the energy demand represents themaximum rate at which the load is expected to consume energy when it isoperating. The decision making sequence may be dependent upon the energydemands of the loads, so that the enablement state decision for a loadhaving a relatively higher energy demand is made before the enablementstate decision for a load having a relatively lower energy demand. Insuch circumstances, each of the sets of load state data is preferablycomprised of an energy demand indication of the energy demand of theload.

The method of the invention may be comprised of making a singleenablement state decision for each of the loads based upon a single setof load state data generated from each of the loads. Preferably,however, the method is performed repeatedly in accordance with aschedule.

The schedule is preferably comprised of at least one period. Preferablythe schedule is comprised of a plurality of periods. Each period ispreferably comprised of a plurality of segments so that each period isdivided into segments. Preferably the method is performed once duringeach segment of each period.

In preferred embodiments, the duty cycles of the loads are definedhaving regard to the periods so that the enablement need of each of theloads is defined by a remaining number of segments in the period duringwhich the load must be in the load enabled state in order to achieve itsduty cycle.

As a result, in preferred embodiments the sets of load state datagenerated during each segment in a period relate to the loads in thecontext of the period and are somewhat interrelated by the determinationof the enablement needs of the loads.

The period may be any length of time. The period may be divided into anynumber of segments. The length of the period and the number of segmentswithin the period are dependent upon the speed with which the method canbe performed and upon the desired degree of control over the loads thatis sought. By way of non-limiting example, in preferred embodiments theperiod is between about two hours and three hours and the number ofsegments in each period is twelve, so that in preferred embodiments thelength of each segment is between about ten minutes and about fifteenminutes.

In the apparatus aspect of the invention which comprises a controller,the controller may be comprised of any structure, device or apparatuswhich is capable of implementing the enablement state decision. Inpreferred embodiments the controller is comprised of a control circuitand a switch. The control circuit is associated with the processor andthe switch is located within the control circuit.

The load may be connected within an energization circuit and the switchmay be actuatable so that the energization circuit is closed when theload is in the load enabled state and so that the energization circuitis open when the load is in the load disabled state. The energizationcircuit is comprised of an energy source for the load. In preferredembodiments the energy source is an electrical energy source.

The load may alternatively be connected within a control line circuitand the switch may be actuatable so that the control line circuit isclosed when the load is in the load enabled state and so that thecontrol line circuit is open when the load is in the load disabledstate. The control line circuit may be configured to provide any type ofcontrol signal or signals for controlling the load, including electricalcontrol signals, optical control signals, acoustic control signals,pneumatic control signals, hydraulic control signals etc. In preferredembodiments the control line circuit is comprised of an electricalcontrol line and provides electrical control signals to the load.

The switch may be comprised of any structure, device or apparatus whichis compatible with the energization circuit and/or the control linecircuit. The nature of the switch may therefore be dependent upon thenature of the energy supply system and/or upon the manner in which theload is normally controlled. The nature of the switch may therefore alsobe dependent upon the nature of the energization circuit and the controlline circuit.

For example, where the energy supply system is an electrical system orwhere the loads are controlled by a control line circuit comprising anelectrical control line, each switch may be comprised of an electricalswitch. The electrical switch may be comprised of a relay or any othersuitable electrical switch. In other embodiments, the switch may becomprised of a valve for controlling the energization circuit and/or thecontrol line circuit. The valve may be comprised of any suitable valve,including a hydraulic valve or a pneumatic valve.

In preferred embodiments the control circuit preferably functions eitherto disconnect the load from an electrical energy source or to disconnectthe load from a control line circuit comprising an electrical controlline which provides low voltage electrical control signals to the load.

The transmitter and/or the receiver may be comprised of any suitabletype of structure, device or apparatus. For example, the transmitterand/or the receiver may be wired or wireless, and the transmitter and/orreceiver may be comprised of a radio frequency device, an infrareddevice, an acoustical device, an optical device etc. Preferably thetransmitter and/or receiver are comprised of radio frequency devices.Preferably the transmitter and/or receiver are wireless devices. Thetransmitter and/or receiver may be configured to operate in accordancewith any suitable communication protocol. In preferred embodiments thetransmitter and/or receiver are configured to comply substantially withan IEEE 802.15.4 standard.

The apparatus of the invention may be further comprised of a sensordevice for sensing the energy demand of the load which is associatedwith the apparatus. The sensor device may be comprised of any type ofsensor device which is suitable for sensing the energy demand of theload. Where the load is comprised of an electrical load, the sensordevice is comprised of an electrical energy sensor device.

The apparatus of the invention may be further comprised of a battery forproviding electrical power to the apparatus. The battery may becomprised of a rechargeable battery, and the apparatus may be furthercomprised of a recharge circuit for recharging the battery.

In preferred embodiments, the recharge circuit for the rechargeablebattery may be comprised of the electrical energy sensor device. Forexample, the electrical energy sensor device may be comprised of atransformer which senses electrical energy in the energization circuitby producing induced electrical energy in a secondary circuit. Thesecondary circuit may be connected within the recharge circuit so thatthe induced electrical energy in the secondary circuit is used torecharge the rechargeable battery.

The apparatus of the invention may be further comprised of a device foradjusting the duty cycle of the load which is used in the method of theinvention. The duty cycle may be adjusted in any manner, such as toprovide an assigned duty cycle for the load, provide a default dutycycle for the load, restore a natural duty cycle of the load, or resetthe duty cycle of the load to a reset value of the duty cycle. Theapparatus of the invention may be further comprised of a visual displayfor providing a visual representation of the duty cycle of the load,which visual representation may include the natural duty cycle of theload, the assigned duty cycle of the load, historical informationregarding the duty cycle of the load etc.

In the computer readable medium aspect of the invention, theinstructions provided by the computer readable medium may be furthercomprised of directing a controller to implement the enablement statedecision for the load. Similarly, in the apparatus aspects of theinvention which comprise the processor, the processor may be programmedto direct a controller to implement the enablement state decision forthe load.

In its various aspects, the invention provides methods, apparatus,computer readable media and systems for use in managing one or moreenergy consuming loads in a group of energy consuming loads. Theinvention is based upon principles of emergence theory. As a result, theinvention enables one or more loads in a group of loads to operateindependently, without negotiation amongst the loads, but usingfundamental rules of behaviour which independently govern each of theloads.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the invention will now be described with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic diagram of an energy supply system associated witha plurality of energy consuming loads, wherein each energy consumingload is connected with an apparatus of the present invention formanaging the corresponding energy consuming load;

FIG. 2 is a detailed schematic diagram of a preferred embodiment of theapparatus shown in FIG. 1 provided for managing the corresponding energyconsuming load;

FIG. 3 is a schematic diagram of the apparatus and the load, as shown inFIG. 2, connected within an energization circuit;

FIG. 4 is a schematic diagram of the apparatus and the load, as shown inFIG. 2, connected within a control line circuit;

FIG. 5 is a flow chart depicting a preferred method for adjusting anddisplaying a duty cycle as part of an overall method for managing one ora group of energy consuming loads;

FIG. 6 is a flow chart depicting a preferred method for performing atime synchronization function as part of an overall method for managingone or a group of energy consuming loads;

FIG. 7 is a flow chart depicting a preferred method for generating loadstate data for a load and transmitting the load state data as part of anoverall method for managing one or a group of energy consuming loads;

FIGS. 8 a and 8 b are a flow chart depicting a preferred method formaking an enablement state decision for a load as part of an overallmethod for managing one or a group of energy consuming loads; and

FIG. 9 is a chart providing the results of an example of the performanceof the methods as depicted in the flow charts of FIGS. 5 through 8 b.

DETAILED DESCRIPTION

Referring to FIG. 1, a typical energy supply system (20) includes aenergy source (22) and is associated with a plurality of energyconsuming loads. An energy consuming load (24) is a device or apparatuswhich consumes energy and which therefore contributes both to the energyconsumption of the energy supply system (20) and the energy demand ofthe energy supply system (20). The energy consuming loads may beorganized into one or more groups of loads. Further, each of the loads,and groups of loads, may be connected or associated with the energysource (22) in any manner permitting the energy source (22) to providethe necessary or required energy to each of the loads.

The present invention is directed at an apparatus (26) for managing anenergy consuming load (24) in a group of energy consuming loadscomprising the energy consuming load (24) and a plurality of otherenergy consuming loads (24 a . . . 24 n). In a preferred embodiment, theload (24) is connected or associated with the apparatus (26) formanaging the energy consuming load (24). Further, each of the pluralityof other loads (24 a . . . 24 n) is also preferably connected orassociated with an apparatus (26 a . . . 26 n) for managing thecorresponding other load (24 a . . . 24 n). In the preferred embodiment,each load (24) and each other load (24 a . . . 24 n) is comprised of anelectrical load. In addition, each load (24) and each other load (24 a .. . 24 n) has an energy demand, being the rate at which the energy isconsumed by the load (24) or the other load (24 a . . . 24 n)respectively.

Each apparatus (26) may be adapted or configured to be compatible withthe particular load (24) or other load (24 a . . . 24 n) to which it isconnected or with which it is associated. However, preferably, thecomponents and configuration of each apparatus (26, 26 a . . . 26 n) issubstantially similar and operates in a substantially similar manner.Thus, the following description of the apparatus (26) for connectionwith the load (24) is also applicable with respect to any additionalapparatuses (26 a . . . 26 n) provided for managing the plurality ofother loads (24 a . . . 24 n) in the group of energy consuming loadswithin the energy supply system (20).

Referring to FIG. 2, the apparatus (26) is preferably comprised of atransmitter (28) configured to transmit a set of load state datagenerated from the load (24) and a receiver (30) configured to receivesets of load state data generated from the other loads (24 a . . . 24n). Although a separate transmitter and receiver may be provided, in thepreferred embodiment, the transmitter (28) and the receiver (30) arecomprised of a single transceiver (32). Any type or configuration oftransceiver (32) capable of, and suitable for, transmitting andreceiving the necessary load state data may be utilized. However,preferably, the transceiver (32) is a wireless transceiver. Moreparticularly, in the preferred embodiment, the transceiver (32) iscomprised of a radio frequency wireless transceiver (32) associated withan antenna (34) for transmitting and receiving the load state data. Thewireless transceiver (32) may operate in accordance with any suitable orcompatible communication protocol. Preferably, the wireless transceiver(32) is configured to comply substantially with an IEEE 802.15.4standard. For example, a ZigBee™ compliant 2.4 GHz wireless platform maybe utilized. ZigBee™ is a trade-mark of the ZigBee Alliance.

Further, the apparatus (26) is preferably comprised of a processor (36)configured to generate the set of load state data from the load (24), tocompile the sets of load state data from the group of loads, and toprocess the compiled sets of load state data in order to make anenablement state decision for the load (24), wherein the enablementstate decision is made independently of the other loads (24 a . . . 24n).

Thus, the processor (36) is associated or connected with the transceiver(32) such that the processor (36) may communicate with the otherapparatuses (26 a . . . 26 n). Specifically, the processor (36)generates the set of load state data from the load (24) for transmissionby the transceiver (32) to the other apparatuses (26 a . . . 26 n).Further, the processor (36) compiles the sets of load state datareceived by the transceiver (32) from the other apparatuses (26 a . . .26 n). The processor (36) then utilizes the compiled sets of load statedata from the group of loads in order to make an enablement statedecision for the load (24).

The processor (36) may be comprised of any known or conventionalcomputer, processing unit or computing device capable of performing thefunctions of the processor (36) as described herein, including theperformance of the algorithms or sets of instructions necessary topermit the enablement state decision for the load (24) to be made by theprocessor (36).

Accordingly, the processor (36) is preferably programmed to perform itsfunctions, and specifically to generate the set of load state data fromthe load (24), to compile the set of load state data from the load (24)with sets of load state data from the other loads (24 a . . . 24 n) andto process the compiled sets of load state data in order to make anenablement state decision for the load (24) independently of the otherloads (24 a . . . 24 n). In the preferred embodiment, the invention isfurther comprised of a computer readable medium (38) for providingcomputer readable instructions for directing the processor (36) toperform its functions as described herein.

As indicated, the enablement state decision reflects an enablement stateof the load (24), wherein the enablement state is either a load enabledstate or a load disabled state. The enablement state decision for theload (24) is made independently of the enablement state decisions madefor any of the other loads (24 a . . . 24 n). In the preferredembodiment, the load enabled state is a state in which the load (24) iscapable of operating, while the load disabled state is a state in whichthe load is not capable of operating.

The apparatus (26) is also preferably comprised of a controller (40) forimplementing the enablement state decision. Thus, the controller (40) isconnected or associated with the processor (36) such that the enablementstate decision made by the processor (36) may be communicated to thecontroller (40) for implementation.

Although the controller (40) may be comprised of any mechanism or devicecapable of implementing the enablement state decision, the controller(40) is preferably comprised of a control circuit (42) and a switch(44). The control circuit (42) and the switch (44) are associated withthe processor (36) for receiving the enablement state decisiontherefrom. Further, as described in detail below, the switch (44) isactuatable between an open state and a closed state in order toimplement the enablement state decision.

Any type of control circuit (42) and compatible switch (44) may be usedwhich are capable of implementing the enablement state decision.However, preferably, the control circuit (42) and the switch (44) arecompatible for use with one or both of an energization circuit (46) forcontrolling an energization-controllable load, as shown in FIG. 3, and acontrol line circuit (48) for controlling a control line-controllableload, as shown in FIG. 4. In the preferred embodiment, the controller(40) is capable of use with both an energization circuit (46) and acontrol line circuit (48) such that the controller (40) is compatiblefor use in controlling either an energization-controllable load or acontrol line-controllable load.

In the preferred embodiment, the control circuit (42) is preferablycomprised of a transistor array such as a Darlington transistor, oftenreferred to as a Darlington pair. In the preferred embodiment the switch(44) is a relay switch comprised of a Double-Pole Double-Throw relaycapable of handling 15 Amperes of load. One of the relay poles isprovided for use with an energization-controllable load, while the otherof the relay poles is provided for use with a control line-controllableload. Alternatively, the switch (44) may be comprised of a Single-PoleSingle-Throw relay in which a single pole may be used for either anenergization-controllable load or a control line-controllable load.

Referring to FIG. 3, the load (24) may be connected within anenergization circuit (46). Preferably, the energization circuit (46) iscomprised of an electrical energy source (50). In the preferredembodiment, the energization circuit (46) is a mains power circuit forcontrolling the power provided to the load (24). In this case, the load(24) is an electrical load, particularly an energization-controllableload. Examples of an energization-controllable load includerefrigerators, freezers, plug-in portable air conditioners and otherequipment and appliances typically “plugged-in” to a standard poweroutlet.

Referring further to FIGS. 2 and 3, the apparatus (26) is connectedwithin the energization circuit (46) between the load (24) and theelectrical energy source (50), such as a power supply or outlet. Moreparticularly, the switch (44) is connected within the energizationcircuit (46) and is actuatable between an open state and a closed statein order to implement the enablement state decision. Specifically, theswitch (44) is actuated to the closed state so that the energizationcircuit (46) is closed when the load (24) is desired to be in the loadenabled state. Conversely, the switch (44) is actuated to the open stateso that the energization circuit (46) is opened when the load (24) isdesired to be in the load disabled state.

For example, where the load (24) is a household freezer, if theprocessor (36) determines that the freezer should be in the loaddisabled state, the controller (40) opens the switch (44) to open thepower or energization circuit (46). As a result, the power supply to thefreezer is interrupted or cut-off and the freezer will not be capable ofturning on. Alternately, if the processor (36) determines that thefreezer should be in the load enabled state, the controller (40) closesthe switch (44) to close the power or energization circuit (46). As aresult, the power supply to the freezer is connected providing power tothe freezer. Thus, the freezer will be capable of turning on. However,the control system of the freezer will actually determine whether toturn the freezer on or off.

Referring to FIG. 4, the load (24) may be connected within a controlline circuit (48). In the preferred embodiment, the control line circuit(48) is comprised of an electrical control line (52) associated with anequipment controller (54) for the load (24). In this case, the load (24)is a control line-controllable load. Examples of a controlline-controllable load include chillers, furnaces, air circulation fans,space heaters, hot water heaters and air conditioners.

Referring further to FIGS. 2 and 4, the apparatus (26) is connectedwithin the control line circuit (48) with the load (24) and theequipment controller (54). More particularly, the switch (44) isconnected within the control line circuit (48), and particularly isconnected within the electrical control line (52). As above, the switch(44) is actuatable between an open state and a closed state in order toimplement the enablement state decision. Specifically, the switch (44)is actuated to the closed state so that the control line circuit (48) isclosed when the load (24) is desired to be in the load enabled state.Conversely, the switch (44) is actuated to the open state so that thecontrol line circuit (48) is opened when the load (24) is desired to bein the load disabled state.

For example, where the load (24) is a circulation fan as shown in FIG.4, if the processor (36) determines that the circulation fan should bein the load disabled state, the controller (40) opens the switch (44) toopen the control line circuit (48), which mimics an off signal for theload (24). As a result, the circulation fan will be turned off.Alternately, if the processor (36) determines that the circulation fanshould be in the load enabled state, the controller (40) closes theswitch (44) to close the control line circuit (48). As a result, thecontrol of the circulation fan is returned to the equipment controller(54), such as a thermostat, and the circulation fan will be capable ofturning on. However, the equipment controller (54) will actuallydetermine whether to turn the circulation fan on or off.

When the apparatus (26) is utilized within an energization circuit (46)or a control line circuit (48), the apparatus (26) is in a control mode.Specifically, the energization circuit (46) preferably provides acontrol mode referred to as a power mains control. The control linecircuit (48) preferably provides a control mode referred to as a controlline signal control. In addition, the apparatus (26) may be utilized ina monitoring mode. The monitoring mode is not a control mode. Rather,the apparatus (26) monitors the load (24) only and transmits load statedata generated from the load (24) to the other apparatuses (26 a . . .26 n). Typically, the monitoring mode is utilized for non-discretionaryor “must-run” loads, such as lighting systems or CO₂ exhaust fans.

In addition, referring to FIG. 2, the apparatus (26) is preferablyfurther comprised of a sensor device (56) for sensing the energy demandof the load (24). Thus, in the preferred embodiment in which the load(24) is an electrical load, the sensor device (56) is comprised of anelectrical energy sensor device. In order to make an enablement statedecision, the processor (36) of the apparatus (26) is preferablyprovided with information concerning the energy demand of the load (24).The sensor device (56) is utilized to provide this information.

In the preferred embodiment, the electrical energy sensor device (56) iscomprised of at least one current sensor (58) and an associatedrectifier or rectifier circuit (60). The current sensor (58) may becomprised of any device or mechanism capable of sensing or detecting acurrent. However, preferably, the current sensor (58) is comprised of acurrent transformer, such as a clamp-on current transformer, for sensingcurrent within a wire and thereby producing a voltage proportional tothe current. For instance, a current transformer may be clamped on toeach individual “hot” or live conductor of a single phase, two-phase orthree-phase alternating current load voltage supply, such as theenergization circuit (46) or mains power from the electrical energysource (50), as shown in FIGS. 3 and 4. Thus, greater than one currentsensor (58) may be utilized. The output of each current transformer,being an alternating current voltage, is then fed or conducted to anassociated rectifier circuit (60).

A separate rectifier circuit (60) may be provided for each currenttransformer or a single rectifier circuit (60) may be provided for allof the current transformers. The rectifier circuit (60) may be comprisedof any known or conventional rectifier capable of converting alternatingcurrent to direct current. In the preferred embodiment, a direct currentvoltage is produced which is proportional to the alternating currentvoltage from the current sensor (58).

Where more than one rectifier circuit (60) is used, the direct currentvoltage from each rectifier circuit (60) may be summed in order todetermine the energy demand of the load (24). If a single rectifiercircuit (60) is used, each of the phases may be measured in sequence andthe direct current voltages may then be summed in order to determine theenergy demand of the load (24). In the preferred embodiment, the directcurrent voltages are summed by the processor (36).

As a result, in the preferred embodiment the apparatus (26) furtherincludes an analog to digital converter (62) for converting each of theanalog direct current voltage readings obtained from a single rectifiercircuit (60) into separate digital readings, which digital readings arethen summed by the processor (36) to produce a single digital signal.The digital signal is produced by the analog to digital converter (62)to facilitate the use and processing of the information by the processor(36). In the preferred embodiment, the processor (36) is comprised ofthe analog to digital converter (62) such that the analog to digitalconverter (62) is contained therein or forms a component of theprocessor (36).

Preferably, electrical power is provided to the apparatus (26) such thatthe apparatus (26) is capable of performing its functions as describedherein. Preferably, the electrical power is provided by one or morebatteries. In the preferred embodiment, the apparatus (26) is comprisedof a rechargeable battery (64) for providing electrical power to theapparatus (26). The rechargeable battery (64) may be re-charged usingany known or conventional charging device or mechanism. However,preferably, the apparatus (26) is further comprised of a rechargecircuit (66) for recharging the battery (64).

Any conventional or known recharge circuit (66) may be used. However, inthe preferred embodiment, the recharge circuit (66) is comprised of theelectrical energy sensor device (56). In particular, the sensor device(56) performs a dual role. First, as indicated above, the sensor device(56) senses or measures the energy demand of the load (24). Second, thesensor device (56) provides power to the recharge circuit (66) in orderto recharge the rechargeable battery (64).

Further, in the preferred embodiment, the apparatus (26) is additionallycomprised of a device (68) for adjusting a duty cycle of the load (24).The duty cycle of the load (24) is the percentage of time that the load(24) must operate in order to satisfy its assigned objectives. A naturalduty cycle defines the percentage of time that the load (24) mustoperate within its environment to provide a particular result or toachieve a particular objective. However, if desired, the load may beassigned a duty cycle. An assigned duty cycle may be either more or lessthat the natural duty cycle of the load (24).

The adjusting device (68) may be used where desired to adjust the dutycycle of the load (24) for any reason, including providing an assignedduty cycle. Any device may be used which is capable of adjusting theduty cycle. Preferably, the adjusting device (68) is operativelyassociated or connected with the processor (36) and is manuallyadjustable to permit the operator of the apparatus (26) to adjust theduty cycle either upwards or downwards as necessary. For instance, theadjusting device (68) may be comprised of a keypad permitting theinputting of a desired duty cycle.

Further, the apparatus (26) preferably includes a display (70) forproviding a visual representation of the duty cycle of the load (24).Thus, the display (70) is also operatively associated or connected withthe processor (36) such that the present or current duty cycle for theload (24) may be provided by the processor (36) to the display (70) andsuch that the adjusted or assigned duty cycle may be displayed as theduty cycle is being adjusted through the adjusting device (68).

As discussed above, the processor (36) is preferably programmed toperform a set of instructions permitting the processor (36) to performone or more of its functions as described herein. In the preferredembodiment, the set of instructions permit the processor (36) to performthe functions necessary to make the enablement state decision for theload (24), independently of the other loads (24 a . . . 24 n). In otherwords, the enablement state decision for the load (24) is made takinginto consideration the sets of load state data from the other loads (24a . . . 24 n), but is made independently of the enablement statedecisions made for the other loads (24 a . . . 24 n) by the otherapparatuses (26 a . . . 26 n). Further, the processor (36) is alsopreferably programmed to direct the controller (40) to implement theenablement state decision for the load (24).

The processor (36) may be programmed in any conventional or known mannerto perform its intended functions and to carry out the necessaryinstructions. In the preferred embodiment, a computer readable medium(38) provides computer readable instructions or an algorithm fordirecting the processor (36) to carry out the functions which are eithernecessary or desirable in order to make the enablement state decision.Further, in the preferred embodiment, the computer readable medium (38)provides computer readable instructions or an algorithm directing thecontroller (40) to implement the enablement state decision for the load(24). Specifically, the instructions direct the processor (36) to directthe controller (40) to implement the enablement state decision.

The computer readable instructions provided by the computer readablemedium (38) may be used to direct any compatible apparatus and processorcapable of carrying out the instructions. However, in the preferredembodiment, the computer readable medium (38) provides computer readableinstructions for directing the preferred embodiment of the apparatus(26) as described herein, including the preferred embodiment of theprocessor (36) and the controller (40).

Further, the present invention is directed at a method for managing agroup of energy consuming loads comprising a plurality of loads (24, 24a . . . 24 n). A method is also provided for managing an energyconsuming load (24) in a group of energy consuming loads comprising theload (24) and a plurality of other loads (24 a . . . 24 n). The methodsmay be performed or carried out utilizing any compatible apparatussuitable for, and capable of, carrying out the methods. However, in thepreferred embodiment, the apparatus (26) as described herein is utilizedto perform the methods. Further, the apparatus (26) is programmed in thepreferred embodiment to carry out instructions for performing themethods. Finally, the computer readable medium (38) provides computerreadable instructions for directing the apparatus (26), including theprocessor (36) and the controller (40), to perform the methods.

In the preferred embodiment, a method is provided for managing a groupof energy consuming loads comprising a plurality of loads. The pluralityof loads preferably includes the load (24) and at least one other load(24 a . . . 24 n). The method includes generating a set of load statedata from each of the loads (24, 24 a . . . 24 n) in the group of loads.The method further includes making an enablement state decision for eachof the loads (24, 24 a . . . 24 n) using the sets of load state datafrom the loads (24, 24 a . . . 24 n). Each of the enablement statedecisions reflects an enablement state of a corresponding load in thegroup of loads. Further, as discussed above, the enablement state iseither a load enabled state or a load disabled state. Each of theenablement state decisions is made independently of the enablement statedecisions for the loads other than the corresponding load. Finally, themethod includes implementing the enablement state decisions.

Further, a method is provided for managing an energy consuming load (24)in a group of energy consuming loads comprising the load (24) and aplurality of other loads (24 a . . . 24 n). The method includesgenerating a set of load state data from the load (24) and compiling theset of load state data generated from the load (24) with sets of loadstate data generated from the other loads (24 a . . . 24 n). Further,the method includes making an enablement state decision for the load(24) using the compiled sets of load state data. As above, theenablement state decision reflects an enablement state of the load (24),wherein the enablement state is either a load enabled state or a loaddisabled state. Further, the enablement state decision is madeindependently of the other loads (24 a . . . 24 n). Finally, the methodincludes implementing the enablement state decision for the load (24).

Thus, in the preferred embodiment, the computer readable medium (38)provides instructions to the apparatus (26) for, and the processor (36)is programmed for, generating the set of load state from the load (24)and compiling the set of load state data from the load (24) with thesets of load state data from the other loads (24 a . . . 24 n). Thus,each apparatus (26) compiles or gathers all available sets of load statedata. In other words, in the preferred embodiment, a set of load statedata is generated for each of the loads (24, 24 a . . . 24 n) in thegroup of loads to be managed and is compiled or gathered by each of theapparatuses (26, 26 a . . . 26 n) associated with each of the loads (24,24 a . . . 24 n) in the group of loads.

Specifically, as discussed above, the transceiver (32) transmits andreceives the various sets of load state data such that the sets of loadstate data may be compiled by the processor (36). The computer readablemedium (38) further provides instructions to the processor (36), or theprocessor (36) is programmed, for processing the compiled sets of loadstate data in order to make the enablement state decision for the load(24). Enablement state decisions are also made for each of the otherloads (24 a . . . 24 n) in the group of loads being managed. Theenablement state decision made for the load (24) is made independentlyof the enablement state decisions made for each of the other loads (24 a. . . 24 n).

Finally, the computer readable medium (38) provides instructions to theprocessor (36), or the processor (36) is programmed, for directing thecontroller (40) to implement the enablement state decision for the load(24). Thus, when managing a group of loads, the enablement statedecision is implemented for each of the load (24) and the other loads(24 a . . . 24 n) in the group of loads.

In all aspects of the invention, the load (24) or at least one of theloads (24, 24 a . . . 24 n) in the group of loads is a discretionaryload. Each of the loads in a group of loads may be either anon-discretionary load or a discretionary load. A non-discretionary loadis a load which must always be in an enabled state, which must beenabled rigidly according to a schedule, which must be enabled rigidlyaccording to a set of constraints, or which must always be available tobe enabled when called upon. A load in the monitoring mode, as discussedabove, is also considered to be a non-discretionary load. Adiscretionary load is a load for which there is some flexibility inoperating within a schedule or within a set of constraints, as long asthe load is capable of achieving its duty cycle.

Further, as discussed above, the load (24) and each of the other loads(24 a . . . 24 n) has a duty cycle. In the preferred embodiment, theduty cycle for at least one of the discretionary loads is less than 100percent. Thus, the duty cycle may be less than 100 percent for the load(24) and/or at least one of the other loads (24 a . . . 24 n). The dutycycle is the percentage of time that the load must operate in order tosatisfy its assigned objectives. Thus, the load must operate less than100 percent of the time to satisfy its assigned objectives.

The enablement state decision for each load (24) and each other load (24a . . . 24 n) is made with a goal of achieving a target systemequilibrium for the group of loads. The target system equilibriumpreferably represents an energy demand for the group of loads (24, 24 a. . . 24 n) which approaches an average energy demand for the group ofloads (24, 24 a . . . 24 n). More preferably, the target systemequilibrium is equal to a sum for all of the loads (24, 24 a . . . 24 n)in the group of loads of a product of the energy demand of one of theloads and the duty cycle of the one of the loads. Thus, for instance,the contribution of the load (24) to the target system equilibrium isthe product of the energy demand of the load (24) and the duty cycle ofthe load (24).

However, each of the load (24) and the other loads (24 a . . . 24 n) inthe group of loads has an enablement need in order to achieve its dutycycle. Although the enablement state decisions are made with a goal ofachieving the target system equilibrium, the enablement state decisionfor each load (24, 24 a . . . 24 n) is constrained by the enablementneed of that load.

The enablement need of each load (24, 24 a . . . 24 n) relates to the“urgency” of the need for that load to be placed in the load enabledstate. Although the enablement need or urgency may be based upon anumber of factors, typically the enablement need is based upon an amountof time in which that load has been in the load enabled state, upon anamount of time remaining for that load to achieve its duty cycle, andupon the duty cycle of that load. Thus, for example, the enablement needwill be more urgent where a load is at risk of not achieving its dutycycle.

Further, the enablement need will also be dependent upon whether theload is a discretionary or a non-discretionary load. A non-discretionaryload has a rigid enablement need. Thus, for non-discretionary loads, orin order to cause a discretionary load to behave as a non-discretionaryload, a load may be assigned a duty cycle of 100 percent. Alternatively,for non-discretionary loads, or in order to cause a discretionary loadto behave as a non-discretionary load, the amount of time which isrequired in order for the load to achieve its duty cycle may beindicated to be an amount which is greater than or equal to the timeremaining for the load to achieve its duty cycle.

Additionally, in the preferred embodiments, the enablement statedecision for each load (24, 24 a . . . 24 n) is constrained by theenergy demands of the loads. Thus, for example, the enablement statedecision for a load which will not cause the target system equilibriumfor the group of loads to be exceeded if the load is placed in the loadenabled state may be more likely to indicate the load enabled state thanthe enablement state decision for a load which will cause the targetsystem equilibrium to be exceeded if the load is placed in the loadenabled state.

In any event, as indicated above, the enablement state decision for eachload (24) and each other loads (24 a . . . 24 n) in a group of loads ismade using the compiled sets of load state data. Each set of load statedata includes information or data concerning or relating to acorresponding load. The information may be comprised of identifyinginformation, operational information or any other information which mayassist in making the enablement state decision for any of the loads.

In preferred embodiments, each set of load state data is comprised of anenablement need indication indicating the enablement need of thecorresponding load, which relates to the extent to which the duty cycleof the corresponding load has been satisfied. Further, each set of loadstate data is comprised of an energy demand indication indicating theenergy demand of the corresponding load, a duty cycle indicationindicating the duty cycle of the corresponding load, a load identifyingindication for identifying the corresponding load and a time indicationfor identifying the time to which the load state data for thecorresponding load relates.

The duty cycle indication may be used to determine the extent to whichthe corresponding load contributes to the target system equilibrium forthe group of loads. Thus, the duty cycle indication may be expresseddirectly as the duty cycle of the corresponding load. From thisinformation, the contribution of that load to the target systemequilibrium may be calculated utilizing the duty cycle indication andthe energy demand indication of the load. However, the duty cycleindication may alternately be indirectly expressed as the contributionof the load to the target system equilibrium. In addition, as discussedpreviously, each of the loads (24, 24 a . . . 24 n) in the group ofloads may be assigned a duty cycle utilizing the duty cycle adjustingdevice (68).

The enablement state decision for each of the loads (24, 24 a . . . 24n) is made independently of each of the other loads in the group.However, although the decisions are made independently, the enablementstate decisions for the group of loads are preferably made in a decisionmaking sequence. The decision making sequence provides the order inwhich the enablement state decision is made for each of the loads (24,24 a . . . 24 n). In the preferred embodiment, the decision makingsequence is dependent upon the sets of load state data, and inparticular, upon one or more of the indications outlined above.

For instance, the decision making sequence may be dependent upon theenablement need of each of the loads (24, 24 a . . . 24 n) as providedin the enablement need indication for each corresponding load. In thisinstance, the enablement state decision for a load having a relativelyhigher enablement need is made before the enablement state decision fora load having a relatively lower enablement need.

Alternately or additionally, the decision making sequence may bedependent upon the energy demand of each of the loads (24, 24 a . . . 24n) as provided in the energy demand indication for each correspondingload. In this instance, the energy demand indication preferablyindicates the maximum rate at which the corresponding load will consumeenergy when it is operating. In this instance, the enablement statedecision for a load having a relatively higher energy demand is madebefore the enablement state decision for a load having a relativelylower energy demand.

Further, in the preferred embodiments, the steps of the methods areperformed, and the sets of instructions are carried out, repeatedly inaccordance with a schedule. The schedule is comprised of at least oneperiod, and preferably a plurality of periods. Each period may be anylength of time, however, preferably the length of each period issubstantially the same or equal. Further, each period is preferablycomprised of a plurality of segments. Each period may be divided intoany number of segments, each segment being of any length of time.However, in the preferred embodiment, each period is divided into anumber of equal time segments.

Further, the steps of the method are performed, and the instructions arecarried out, one time during each segment of each period. Thus, thelength of time of the period and the number of segments within theperiod are selected depending, at least in part, upon the speed at whichthe steps in the methods can be performed or the instructions carriedout. Further, the length of time of the period and the number ofsegments within the period are also selected depending upon the desireddegree of control over the loads which is desired to be achieved. Asstated, the steps of the method are performed, and the instructions arecarried out, one time during each segment of each period. Thus, greatercontrol tends to be provided as the number of segments increases foreach period or as the length of time of each segment decreases.

In the preferred embodiments, each period is between about two hours andthree hours and the number of segments in each period is twelve. As aresult, the length of each segment is between about ten minutes andabout fifteen minutes.

Further, in preferred embodiments, the duty cycle of each load isdefined having regard to the periods. Thus, the enablement need of eachof the loads (24, 24 a . . . 24 n) is preferably defined by a remainingnumber of segments in the period during which the load must be in theload enabled state in order to achieve its duty cycle

Referring to FIGS. 5-8 b, in the preferred embodiment, four processes orsets of instructions are conducted concurrently or as required toperform the methods of the invention, resulting in the making andimplementing of the enablement state decision for the load (24). Thegoal of the processes or sets of instructions is to manage the energydemand of the energy consuming load (24) and to manage the collectiveenergy demand of a group of energy consuming loads, including the load(24) and the plurality of other loads (24 a . . . 24 n). Moreparticularly, in the preferred embodiment, the goal is to manage orcontrol the peak energy demand in each instance by achieving the targetsystem equilibrium for the group of loads. This goal is accomplished bymaking an enablement state decision with respect to each load (24) andeach other load (24 a . . . 24 n) which takes into account the loadstate data of all loads but is made independently of the other loads.

In the preferred embodiment, the four processes or sets of instructionsare set out in the flow charts shown in FIGS. 5-8 b. First, referring toFIG. 5, a set of instructions or an algorithm is provided for adjustingand displaying the duty cycle of the load (24). It is understood thatthe same processes or sets of instructions would be carried out for eachof the other loads (24 a . . . 24 n) as well. In FIG. 5:

-   -   r_(DC)—refers to the duty cycle ratio (as a percentage of        required on-time in a period or required time in an enabled        state);    -   DC_(INC)—refers to the increment and decrement value for r_(DC).

Referring to the flow chart of FIG. 5, the current duty cycle ratio“r_(DC)” for the load (24), expressed as a percentage of required“on-time” or percentage of time that the load (24) is required tooperate in a period, is displayed (72). For exemplary purposes only, theflow chart indicates a duty cycle of 50%. In the preferred embodiment,the current duty cycle ratio “r_(DC)” is displayed on the display (70).

If the duty cycle ratio “r_(DC)” is desired to be incremented (74), theduty cycle ratio is adjusted upwardly utilizing the duty cycle adjustingdevice (68). The adjusted duty cycle ratio “r_(DC)” is determined (76)as the sum of the current duty cycle ratio “r_(DC)” and the desiredincrement value for the duty cycle ratio “DC_(INC)”. A determination(78) is then made as to whether the adjusted duty cycle ratio is greaterthan 100%. If the adjusted duty cycle ratio is not greater than 100%,the adjusted duty cycle ratio “r_(DC)” is displayed (72) as the newcurrent duty cycle ratio. If the adjusted duty cycle ratio is greaterthan 100%, then the adjusted duty cycle ratio is set at 100% (80) and isdisplayed (72) as the new current duty cycle ratio.

If the duty cycle ratio “r_(DC)” is desired to be decremented (82), theduty cycle ratio is adjusted downwardly utilizing the duty cycleadjusting device (68). The adjusted duty cycle ratio “r_(DC)” isdetermined (84) by deducting or subtracting the desired decrement valuefor the duty cycle ratio “DC_(INC)” from the current duty cycle ratio“r_(DC)”. A determination (86) is then made as to whether the adjustedduty cycle ratio is less than 0%. If the adjusted duty cycle ratio isnot less than 0%, the adjusted duty cycle ratio “r_(DC)” is displayed(72) as the new current duty cycle ratio. If the adjusted duty cycleratio is less than 0%, then the adjusted duty cycle ratio is set at 0%(88) and is displayed (72) as the new current duty cycle ratio.

Second, referring to FIG. 6, a set of instructions or an algorithm isprovided for performing a time-keeping or time synchronization function.In the preferred embodiment within a network comprising the use of aplurality of apparatuses (26, 26 a . . . 26 n) for use with a group ofloads (24, 24 a . . . 24 n), a single apparatus (26) is selected toperform the time-keeping function. Specifically, the selected apparatus(26), and particularly the processor (36) of the selected apparatus(26), will cause a timing pulse to be generated and transmitted to theother apparatuses (26 a . . . 26 n) such that the functions oractivities of the network of apparatuses (26, 26 a . . . 26 n) may becoordinated to perform the overall methods of the present invention. Atiming pulse may be transmitted at any desired time intervals. However,preferably, a timing pulse is transmitted at the start of each newsegment within the period. Thus, in the preferred embodiment, a timingpulse is transmitted about every 10 to 15 minutes. In FIG. 6:

-   -   n_(s)—refers to the current time segment number within the        period;    -   t_(s)—refers to the time elapsed in the current time segment;    -   C_(L)—refers to the length of time of a time segment;    -   N_(smax)—refers to the total number of time segments in the        period.

Any unit of time may be used in the invention. In the preferredembodiment the unit of time is seconds so that t_(s) and C_(L) are bothexpressed in seconds.

To commence the time synchronization operation (90), the current timesegment number “n_(s)” and the number of seconds elapsed in the currenttime segment “t_(s)” are determined. For exemplary purposes, at thecommencement of the operation (90), the current time segment number isindicated as zero (0). Further, in the preferred embodiment, the timingpulse is transmitted at the start of every segment. Thus, in thisexample, the number of seconds elapsed in the current time segment isindicated as zero (0). Accordingly, the current time segment number isbroadcast or transmitted (92) when zero seconds have elapsed in thecurrent time segment.

A determination (94) is then made regarding whether or not the number ofseconds elapsed in the current time segment “t_(s)” is greater than orequal to the length of time of the time segment “C_(L)”. If the numberof seconds elapsed in the current time segment “t_(s)” is less than thelength of time of the time segment “C_(L)”, the number of secondselapsed in the current time segment is incremented by one second (96)and the determination step (94) is repeated. In other words, thedetermination step (94) is repeated every second until the number ofseconds elapsed in the current time segment “t_(s)” is greater than orequal to the length of time of the time segment “C_(L)”.

When the determination (94) is made that the number of seconds elapsedin the current time segment “t_(s)” is greater than or equal to thelength of time of the time segment “C_(L)”, the current time segment isadjusted (98) or a new current time segment is determined. The adjustedor new current time segment “n_(s)” is determined by increasing thecurrent time segment by one (n_(s)+1).

The question (100) is then posed as to whether the adjusted or newcurrent time segment “n_(s)” is greater than or equal to the totalnumber of time segments in the period “N_(smax)”. If the adjusted or newcurrent time segment “n_(s)” is less than the total number of timesegments in the period “N_(smax)”, then the adjusted or new current timesegment number is broadcast (92). Thus, for exemplary purposes, theadjusted or new current time segment number, being one “1”, will bebroadcast or transmitted (92) when zero seconds have elapsed in theadjusted or new current time segment.

If the adjusted or new current time segment “n_(s)” is greater than orequal to the total number of time segments in the period “N_(smax)”,then the current time segment number is reset (102) to zero (0) andsubsequently broadcast (92). Specifically, for exemplary purposes, thereset current time segment number, being zero, will be broadcast ortransmitted (92) when zero seconds have elapsed in the reset currenttime segment.

Third, referring to FIG. 7, a set of instructions or an algorithm isprovided for generating a set of load state data for the load (24) andtransmitting the load state data. In the preferred embodiment, theprocessor (36) of each apparatus (26, 26 a . . . 26 n) in the networkgenerates a set of load state data for the corresponding load (24, 24 a. . . 24 n) at the commencement of each segment. This load state data isthen transmitted to each of the other apparatuses (26, 26 a . . . 26 n)by their respective transmitters (28). Thus, in the preferredembodiment, the set of load state data for the corresponding load isgenerated and transmitted about every 10 to 15 minutes. In FIG. 7:

-   -   n_(s)—refers to the current time segment number within the        period and provides the “time indication” of the time to which        the set of load state data relates;    -   n_(on)—refers to the number of time segments within the period        that the load has been in the load enabled state;    -   n_(SN)—refers to the number of segments within the period needed        to fulfill the duty cycle of the load and provides the        “enablement need indication” of the enablement need of the load;    -   I_(MAX)—refers to the maximum load measurement and provides the        “energy demand indication” of the energy demand of the load;    -   I_(CURR)—refers to the current load reading or current load        measurement;    -   I_(CSE)—refers to the contribution of the load to the target        system equilibrium;    -   ID—refers to the unique identification number for the apparatus        (26, 26 a . . . 26 n) and provides the “load identifying        indication” identifying the load to which the set of load state        data relates;    -   r_(DC)—refers to the duty cycle ratio (as a percentage of        required on-time or time in an enabled state for the load in a        period) and provides the “duty cycle indication” of the duty        cycle of the load;    -   N_(smax)—refers to the total number of time segments in the        period.

To commence the operation (104), the current time segment numberbroadcast (92) as the timing pulse in the operation of FIG. 6 isreceived, preferably by the receiver (30) of each apparatus (26, 26 a .. . 26 n) in the network. Upon receipt of the timing pulse, ameasurement or reading of the current load “I_(CURR)” is generated(106). If the current load includes more than one phase, then I_(CURR)represents the sum of the measurements for the phases. In the preferredembodiment, the sensor device (56) is utilized to provide the necessaryreading or measurement. If the apparatus (26) is the apparatus (26)which is performing the time-keeping function, then the apparatus (26)implicitly receives the timing pulse and generates the measurement ofI_(CURR).

A determination (108) is then made as to whether the current load“I_(CURR)” is greater than the maximum load “I_(MAX)” previouslymeasured by the sensor device (56) or previously provided to theprocessor (36). The maximum load measurement is utilized to provide theenergy demand indication with respect to the corresponding load. If thecurrent load measurement is greater than the maximum load measurement,the maximum load measurement, and thus the energy demand indication, isupdated or reset to correspond with or be equal to the current loadmeasurement (110). The reset or updated maximum load measurement“I_(MAX)” is subsequently further processed in the next step (112) ofthe operation. If the current load measurement is not greater than themaximum load measurement, the maximum load measurement “I_(MAX)” is notrest or updated prior to further processing in the next step (112) ofthe operation.

The next step (112) of the operation is comprised of a calculation orgeneration of the contribution of the load to the target systemequilibrium “I_(CSE)”. In particular, the contribution of the load tothe target system equilibrium “I_(CSE)” is the product of the duty cycleof the load or the duty cycle indication (“r_(DC)”) and the maximum loadmeasurement or energy demand indication for the load (“I_(MAX)”). Thesum of the contributions for all of the loads in the group of loadsprovides the target system equilibrium. The next step (112) of theoperation is further comprised of a calculation or generation of thecurrent number of segments within the period for which the load must bein an enabled state in order to fulfill its duty cycle “n_(SN)”, beingthe enablement need indication.

In particular, the current enablement need indication “n_(SN)” iscalculated by subtracting the number of time segments that the load (24)has been enabled or is in the enabled state “n_(on)” during the periodfrom the total number of time segments within the period which areneeded to fulfill the duty cycle of the load “n_(SN)”. In other words,n_(SN)(current)=n_(SN)(total)−n_(on). The calculation of n_(SN)(current) is performed for each segment using the value of n_(SN)(total) which is applicable to the current duty cycle of the load. As aresult, in circumstances where the duty cycle of the load is adjustedbetween segments, the value of n_(SN) (total) which is used to calculaten_(SN) (current) will change to reflect the adjustment of the duty cycleof the load.

Finally, the load state data concerning the load (24) generated by theprocessor (36) is broadcast (114) or transmitted. Specifically, the loadstate data concerning the load (24) is transmitted by the transmitter(28) of the apparatus (26) for receipt by the receiver (30) of each ofthe other apparatuses (26 a . . . 26 n). In the preferred embodiment,the load state data which is broadcast (114) includes the loadidentifying indication “ID”, the energy demand indication “I_(MAX)”, thecurrent enablement need indication “n_(SN)”, the contribution to thetarget system equilibrium “I_(CSE)” and the time indication “n_(s)”. Asdiscussed previously, the contribution to the target system equilibrium“I_(CSE)” is calculated from, and thus includes information concerning,the duty cycle indication “r_(DC)”.

Fourth, referring to FIGS. 8 a and 8 b, a set of instructions or analgorithm is provided for further processing the sets of load state dataconcerning the load (24) and the other loads (24 a . . . 24 n) andmaking an enablement state decision for the load (24).

In the preferred embodiment, each segment of the period is furtherdivided into four sub-segments. During the first sub-segment, thesynchronization information or timing pulse is received by the apparatus(26). The first sub-segment occurs over a relatively short period oftime. During the second sub-segment, the apparatus (26) transmits theload state data for the load (24) and receives the load state data foreach of the other loads (24 a . . . 24 n). The second sub-segment alsooccurs over a relatively short period of time. The portion of the secondsub-segment in which the apparatus (26) receives the load state dataconcerning the other loads (24 a . . . 24 n) is shown in the flow chartof FIG. 8 a. During the third sub-segment, the processor (36) makes theenablement state decision for the load (24). The third sub-segment isshown in the flow chart of FIG. 8 b and occurs over a relatively shortperiod of time. Finally, the fourth sub-segment is a “do-nothing”segment. If the load (24) is actuated to an enabled state by thecontroller (40), the load (24) will function as if the apparatus (26)were not present. If the load (24) is actuated to a disabled state bythe controller (40), the load (24) will either be turned off or remainoff. In FIGS. 8 a and 8 b:

-   -   n_(s)—refers to the current time segment number within the        period (the “time indication”);    -   n_(ON)—refers to the number of time segments within the period        that the load has been in the load enabled state;    -   n_(SN)—refers to the number of segments within the period needed        to fulfill the duty cycle of the load (the “enablement need        indication”);    -   n_(L)—refers to the current n_(SN) level of the previously        processed load;    -   I_(MAX)—refers to the maximum load measurement (the “energy        demand indication”);    -   I_(CSE)—refers to the contribution of the load to the target        system equilibrium;    -   I_(TSE)—refers to the target system equilibrium;    -   I_(GT)—refers to the gap to the target system equilibrium;    -   I_(CUMSL)—refers to the computed cumulative system load, being        the sum of I_(MAX) for all loads (24, 24 a . . . 24 n) in the        group of loads being managed which are assumed to be enabled;    -   ID—refers to the unique identification number for the apparatus        (the “load identifying indication”);    -   t_(rcv)—refers to the window or sub-segment for receiving the        load state data from the other loads (24 a . . . 24 n);    -   N_(smax)—refers to the total number of time segments in the        period;    -   S_(CTRL)—refers to the computed enablement state decision, being        either an enabled state or a disabled state;    -   I_(SED)—refers to the target system equilibrium deficit over the        period.

Referring to the flow chart of FIG. 8 a, a set of instructions or analgorithm is provided for receiving the load state data concerning theother loads (24 a . . . 24 n). The operation commences with a query(116) as to whether the current time segment number “n_(s)” is zero (0).If the current time segment number is zero, the target systemequilibrium deficit “I_(SED)” and the number of time segments that theload (24) has been enabled “n_(ON)” are reset (118) to zero (0). If thecurrent time segment number is not zero, or once the reset operation(118) has been performed, the remaining steps in the process areconducted. Specifically, the remaining steps, as set out below, arerepeated for each set of load state data received from each otherapparatus (26 a . . . 26 n) for its corresponding other load (24 a . . .24 n).

First, the set of load state data for the other load (24 a . . . 24 n)is received (120) by the apparatus (26). In the preferred embodiment, asdescribed above, the set of load state data includes the loadidentifying indication “ID”, the energy demand indication “I_(MAX)”, thecurrent enablement need indication “n_(SN)”, the contribution to thetarget system equilibrium “I_(CSE)” and the time indication “n_(s)”.Second, the load state data is initially processed (122). In particular,the target system equilibrium “I_(TSE)” is updated to reflect thecurrent load state data being received. Further, the load state data forthe other load is saved. Finally, all of the sets of load state datareceived by the apparatus (26) are sorted in descending order accordingto the n_(SN) (current enablement need indication) and the I_(MAX)(energy demand indication). Specifically, the sets of load state dataare first or primarily sorted according to the enablement needindication, in descending order or from the greatest enablement need tothe least enablement need. Where one or more loads has the sameenablement need indication, those sets of load state data aresecondarily sorted according to the energy demand indication, indescending order or from the greatest energy demand to the least energydemand.

A determination (124) is then made regarding whether the window orsub-segment for receiving the load state data has expired. If the windowhas not expired, further load state data is received (120) and initiallyprocessed (122). If the window has expired, the further steps set out inthe flow chart of FIG. 8 b are performed. Specifically, the flow chartof FIG. 8 a and the flow chart of FIG. 8 b are connected or related toeach other at point designations “A” and “B”.

Referring to the flow chart of FIG. 8 b, a set of instructions or analgorithm is provided for making the enablement state decision for eachload (24, 24 a . . . 24 n). Specifically, the steps of FIG. 8 b formaking the enablement state decisions are performed by each apparatus(26, 26 a . . . 26 n) in the network in order to calculate or determinean enablement state decision for each load (24, 24 a . . . 24 n) withinthe group of loads. However, although enablement state decisions arecalculated for each load (24, 24 a . . . 24 n), the processor (36) ofeach apparatus (26, 26 a . . . 26 n) only implements the enablementstate decision for its corresponding load.

The enablement state decisions for the loads (24, 24 a . . . 24 n) aremade according to the decision making sequence, which is preferablyprovided by or determined by the enablement need and the energy demandof the loads. In the preferred embodiment, the decision making sequenceis comprised of the descending order of the sets of load state data asdetermined in the initial processing step (122) of FIG. 8 a. In otherwords, the enablement state decision will be made for each load (24, 24a . . . 24 n) in sequence starting from the load having the greatestenablement need and energy demand and ending with the load having theleast or lowest enablement need and energy demand. Once the apparatusmakes or determines the enablement state decision for its respective orcorresponding load, no subsequent enablement state decisions need bedetermined by that apparatus. Rather, the processor (36) of theapparatus will direct the controller (40) to implement the enablementstate decision for its respective or corresponding load.

Referring to FIG. 8 b, for exemplary purposes, at the commencement ofthe process prior to processing the load state data to make theenablement state decision for the first load in the decision makingsequence, the computed cumulative system load “I_(CUMSL)” is zero (126).The gap to the target system equilibrium “I_(GT)” is then determined(128). Specifically, the I_(GT) is equal to the target systemequilibrium “I_(TSE)” less the computed cumulative system load“I_(CUMSL)”, plus the system equilibrium deficit “I_(SED)” if theI_(SED) is greater than zero. A series of queries are then made.

The first query (130) is whether the number of segments needed tofulfill the duty cycle of the corresponding load “n_(SN)” is zero (0).If the n_(SN) is zero, the computed enablement state decision “S_(CTRL)”is determined or assumed to be the disabled state (132). In other words,if there is no need for this load to operate, it is assumed to bedisabled.

If the n_(SN) is not zero, the second query (134) is made as to whetherthe computed cumulative system load “I_(CUMSL)” is zero (0). If theI_(CUMSL) is zero, the computed enablement state decision “S_(CTRL)” isdetermined or assumed to be the enabled state (136). Further, theI_(CUMSL) is re-calculated, reset or updated to take into account thecurrent I_(CUMSL) and the maximum load measurement “I_(MAX)” As well, ifno loads have thus far been determined or assumed to be in the enabledstate, an assumption is typically made that this load will be determinedto be in the enabled state.

If the I_(CUMSL) is not zero, a third query (138) is made as to whetherthe current number of segments needed to fulfill the duty cycle of thecorresponding load “n_(SN)” is greater than or equal to the remainingnumber of segments in the period. The current number of segments neededto fulfill the duty cycle of the load is determined by subtracting“n_(on)” from the total number of segments within the period which areneeded to fulfill the current duty cycle of the load “n_(SN)”. Theremaining number of segments in the period is determined by subtractingthe current time segment number “n_(s)” from the total number of timesegments in the period “N_(smax)”. If the answer to the query is “yes”,the computed enablement state decision “S_(CTRL)” is determined orassumed to be the enabled state and the I_(CUMSL) is re-calculated,reset or updated (136). In other words, the load is assumed to beenabled as time is running out for the load to meet its duty cyclerequirements.

If the answer to the third query (138) is “no”, a fourth query (140) ismade as to whether the computed cumulative system load “I_(CUMSL)” isgreater than the target system equilibrium “I_(TSE)”. If the I_(CUMSL)is greater than the I_(TSE), the computed enablement state decision“S_(CTRL)” is determined or assumed to be the disabled state (132). Inother words, as the target system equilibrium has been reached, it maybe assumed that no further loads will be enabled.

If the I_(CUMSL) is not greater than the I_(TSE), a fifth query (142) ismade as to whether the gap to the target system equilibrium “I_(GT)” isgreater than zero (0). If the I_(GT) is not greater than zero, thecomputed enablement state decision “S_(CTRL)” is determined or assumedto be the disabled state (132).

If the I_(GT) is greater than zero, a sixth query (144) is made as towhether the maximum load measurement “I_(MAX)” or energy demand of theload is less than the gap to the target system equilibrium “I_(GT)”. Ifthe answer to the sixth query (144) is “yes”, the computed enablementstate decision “S_(CTRL)” is determined or assumed to be the enabledstate and the I_(CUMSL) is re-calculated, reset or updated (136). Inother words, as a gap still exists which will not be exceeded by theload, it is assumed that this load is enabled.

If the answer to the sixth query (144) is “no”, a seventh query (146) ismade as to: (a) whether the maximum load measurement “I_(MAX)” or energydemand of the load is less than or equal to twice the gap to the targetsystem equilibrium “I_(GT)”; and (b) whether the number of segmentscurrently needed to fulfill the duty cycle of the present load “n_(SN)”is equal to the current n_(SN) level “n_(L)”, being the current n_(SN)of the previously processed load. If the answer to both enquiries of theseventh query (146) is “yes”, the computed enablement state decision“S_(CTRL)” is determined or assumed to be the enabled state and theI_(CUMSL) is re-calculated, reset or updated (136).

The second question (b) of the seventh query (146) relates toidentifying whether the given or present load is of the same need as thepreviously processed load, i.e., whether the loads are of a common needlevel. Thus, the first question (a) is only determined (i.e. allowing anovershoot of the I_(TSE)) on loads with the same need level. If thegiven load is of a lesser need than the previous load, it should not beallowed to overshoot the I_(TSE) once higher priority loads have had achance to be enabled. This allows a scheduling algorithm whereby theI_(TSE) is overshot at the first opportunity if the overshoot is lowerin magnitude than the undershoot for loads of the same need level. Thiswill avoid the case where in the last segment, it is determined that allloads must be enabled (thereby potentially causing a peak load valueequal to the theoretical maximum).

If the answer to either of the enquiries of the seventh query (146) is“no”, no action is taken and the current n_(SN) level of the previouslyprocessed load (n_(L)) is simply reset or updated to the current n_(SN)of the present or given load (148). Similarly, once the computedenablement state decision “S_(CTRL)” is determined or assumed to be thedisabled state (132), the current n_(SN) level of the previouslyprocessed load (n_(L)) is also reset or updated to the current n_(SN) ofthe present or given load (148).

Once the computed enablement state decision “S_(CTRL)” is determined orassumed to be the enabled state (136), a determination (150) is made asto whether the enabled state decision made by the apparatus relates toits corresponding load. If the enablement state decision does not relateto its corresponding load, the current n_(SN) level “n_(L)” is simplyreset or updated to the n_(SN) of the present or given load (148) and nofurther action is taken. However, if the enablement state decision doesrelate to its corresponding load, the processor (36) directs thecontroller (40) to implement the enablement state decision to actuatethe load to the enabled state. Further, the number of time segments thatthe load has been in the enabled state “n_(ON)” is updated to equal thecurrent n_(ON) plus one (1). As well, the current n_(SN) level of thepreviously processed load (n_(L)) is subsequently reset or updated tothe n_(SN) of the present or given load (148).

Finally, once the n_(SN) level “n_(L)” is reset or updated (148), adetermination (154) is made regarding whether the process, as describedabove, has been conducted for all of the available sets of load statedata. If it has not, the process is continued by returning to the step(128) for determining the gap to the target system equilibrium “I_(GT)”and performing the first to seventh queries for the next load in thedecision making sequence. If the process has been conducted for all ofthe available sets of load state data, an updated or reset systemequilibrium deficit over the period “I_(SED)” is determined orcalculated (156) based upon the given or present I_(SED), as well as thetarget system equilibrium “I_(TSE)” and the computed cumulative systemload “I_(CUMSL)”.

The algorithm then proceeds back to FIG. 8( a) at point designation “B”.

EXAMPLE

The following example serves more fully to illustrate the invention. Inparticular, FIG. 9 provides the results of an example of the performanceof the algorithms or sets of instructions provided in the flow charts ofFIGS. 5 through 8 b by the apparatus (26). For the example, the periodis comprised of 12 segments and the group of loads is comprised of threeloads, being the load (24) and two other loads (24 a, 24 b), having thefollowing characteristics:

I_(CSE) I_(MAX) Watts n_(SN) Watts r_(DC) % Contribution to segments MaxDuty system in Period n_(SN) Load # Load Cycle equilibrium neededrounded 1 500 55% 275 6.6 7 2 1000 40% 400 4.8 5 3 1500 30% 450 3.6 4I_(TSE) 1125

The results are set out in FIG. 9 for each of the three loads and foreach of the twelve segments of the period. As shown in FIG. 9, theresulting average load for the period is 1208.333 Watts, while the peakload or peak energy demand for the period is 1500 Watts.

Finally, in this document, the word “comprising” is used in itsnon-limiting sense to mean that items following the word are included,but items not specifically mentioned are not excluded. A reference to anelement by the indefinite article “a” does not exclude the possibilitythat more than one of the elements is present, unless the contextclearly requires that there be one and only one of the elements.

1. A method for managing a group of energy consuming loads comprising aplurality of loads, the method comprising: (a) generating a set of loadstate data from each of the loads in the group of loads, wherein atleast one of the loads in the group of loads is comprised of adiscretionary load, wherein each of the loads in the group of loads hasa duty cycle, wherein each of the loads in the group of loads has anenergy demand and wherein the duty cycle for at least one of thediscretionary loads is less than 100 percent; (b) making an enablementstate decision for each of the loads using the sets of load state datafrom the loads, wherein each of the enablement state decisions reflectsan enablement state of a corresponding load in the group of loads,wherein the enablement state is either a load enabled state or a loaddisabled state, wherein each of the enablement state decisions is madeindependently of the enablement state decisions for the loads other thanthe corresponding load, wherein the enablement state decisions are madewith a goal of achieving a target system equilibrium for the group ofloads, and wherein the target system equilibrium is equal to a sum forall of the loads in the group of loads of a product of the energy demandof one of the loads and the duty cycle of the one of the loads; and (c)implementing the enablement state decisions.
 2. The method as claimed inclaim 1 wherein each of the loads in the group of loads is an electricalload.
 3. The method as claimed in claim 1 wherein each of the loads inthe group of loads has an enablement need in order to achieve its dutycycle and wherein the enablement state decisions are constrained by theenablement needs of the loads.
 4. The method as claimed in claim 1wherein the enablement state decisions for the group of loads are madein a decision making sequence.
 5. The method as claimed in claim 4wherein each of the loads in the group of loads has an enablement needin order to achieve its duty cycle and wherein the decision makingsequence is dependent upon the enablement need of each of the loads. 6.The method as claimed in claim 5 wherein the decision making sequence isfurther dependent upon the energy demand of each of the loads.
 7. Themethod as claimed in claim 4 wherein the decision making sequence isdependent upon the energy demand of each of the loads.
 8. The method asclaimed in claim 1, further comprising repeating (a), (b) and (c) inaccordance with a schedule.
 9. The method as claimed in claim 8 whereinthe schedule is comprised of at least one period.
 10. The method asclaimed in claim 9 wherein the period is comprised of a plurality ofsegments.
 11. The method as claimed in claim 10 wherein the enablementstate decisions for the group of loads are made in a decision makingsequence.
 12. The method as claimed in claim 11 wherein each of theloads in the group of loads has an enablement need in order to achieveits duty cycle, wherein the decision making sequence is dependent uponthe enablement need of each of the loads, and wherein the enablementneed of each of the loads is defined by a remaining number of segmentsin the period during which the load must be in the load enabled state inorder to achieve its duty cycle.
 13. The method as claimed in claim 12wherein the decision making sequence is further dependent upon theenergy demand of each of the loads.
 14. The method as claimed in claim11 wherein the decision making sequence is dependent upon the energydemand of each of the loads.
 15. The method as claimed in claim 1,further comprising assigning the duty cycle to each of the loads in thegroup of loads.
 16. The method as claimed in claim 1 wherein each of theloads in the group of loads has an enablement need in order to achieveits duty cycle, and wherein each of the sets of load state data from thegroup of loads is comprised of an enablement need indication of theenablement need of the load and an energy demand indication of theenergy demand of the load.
 17. The method as claimed in claim 16 whereineach of the sets of load state data from the group of loads is furthercomprised of a duty cycle indication of the duty cycle of the load. 18.The method as claimed in claim 17 wherein the enablement state decisionis constrained by the enablement need of the load.
 19. The method asclaimed in claim 17 wherein each of the sets of load state data from thegroup of loads is further comprised of a load identifying indicationidentifying the load and a time indication of a time to which the set ofload state data relates.
 20. A method for managing an energy consumingload in a group of energy consuming loads comprising the load and aplurality of other loads, the method comprising: (a) generating a set ofload state data from the load, wherein the load is comprised of adiscretionary load, wherein the load has a duty cycle and wherein theduty cycle for the load is less than 100 percent; (b) compiling the setof load state data generated from the load with sets of load state datagenerated from the other loads; (c) making an enablement state decisionfor the load using the compiled sets of load state data, wherein theenablement state decision reflects an enablement state of the load,wherein the enablement state is either a load enabled state or a loaddisabled state, wherein the enablement state decision is madeindependently of the other loads, wherein the enablement state decisionis made with a goal of achieving a target system equilibrium for thegroup of loads, wherein each of the loads in the group of loads has anenergy demand and wherein the target system equilibrium is equal to asum for all of the loads in the group of loads of a product of theenergy demand of one of the loads and the duty cycle of the one of theloads; and (d) implementing the enablement state decision for the load.21. The method as claimed in claim 20 wherein each of the loads in thegroup of loads is an electrical load.
 22. The method as claimed in claim20 wherein the load has an enablement need in order to achieve its dutycycle and wherein the enablement state decision is constrained by theenablement need of the load.
 23. The method as claimed in claim 20wherein the enablement state decisions for the group of loads are madein a decision making sequence.
 24. The method as claimed in claim 23wherein each of the loads in the group of loads has an enablement needin order to achieve its duty cycle and wherein the decision makingsequence is dependent upon the enablement need of each of the loads. 25.The method as claimed in claim 24 wherein the decision making sequenceis dependent upon the energy demand of each of the loads.
 26. The methodas claimed in claim 23 wherein the decision making sequence is dependentupon the energy demand of each of the loads.
 27. The method as claimedin claim 20, further comprising repeating (a), (b), (c) and (d) inaccordance with a schedule.
 28. The method as claimed in claim 27wherein the schedule is comprised of at least one period.
 29. The methodas claimed in claim 28 wherein the period is comprised of a plurality ofsegments.
 30. The method as claimed in claim 29 wherein the enablementstate decisions for the group of loads are made in a decision makingsequence.
 31. The method as claimed in claim 30 wherein each of theloads in the group of loads has an enablement need in order to achieveits duty cycle, wherein the decision making sequence is dependent uponthe enablement need of each of the loads, and wherein the enablementneed of each of the loads is defined by a remaining number of segmentsin the period during which the load must be in the load enabled state inorder to achieve its duty cycle.
 32. The method as claimed in claim 20further comprising assigning the duty cycle to the load.
 33. The methodas claimed in claim 20 wherein each of the loads in the group of loadshas an enablement need in order to achieve its duty cycle, and whereineach of the sets of load state data from the group of loads is comprisedof an enablement need indication of the enablement need of the load andan energy demand indication of the energy demand of the load.
 34. Themethod as claimed in claim 33 wherein each of the sets of load statedata from the group of loads is further comprised of a duty cycleindication of the duty cycle of the load.
 35. The method as claimed inclaim 34 wherein the enablement state decision is constrained by theenablement need of the load.
 36. The method as claimed in claim 34wherein each of the sets of load state data from the group of loads isfurther comprised of a load identifying indication identifying the loadand a time indication of a time to which the set of load state datarelates.
 37. A computer readable medium providing computer readableinstructions for directing a processor to make an enablement statedecision reflecting an enablement state of an energy consuming load in agroup of energy consuming loads comprising the load and a plurality ofother loads, wherein the enablement state is either a load enabled stateor a load disabled state, the instructions comprising: (a) generating aset of load state data from the load; (b) compiling the set of loadstate data from the load with sets of load state data from the otherloads; and (c) processing the compiled sets of load state data in orderto make the enablement state decision independently of the other loads,wherein the enablement state decision is made with a goal of achieving atarget system equilibrium for the group of loads, wherein each of theloads in the group of loads has an energy demand, wherein each of theloads in the group of loads has a duty cycle, and wherein the targetsystem equilibrium is equal to a sum for all of the loads in the groupof loads of a product of the energy demand of one of the loads and theduty cycle of the one of the loads.
 38. The computer readable medium asclaimed in claim 37 wherein the load has an enablement need in order toachieve its duty cycle and wherein the enablement state decision isconstrained by the enablement need of the load.
 39. The computerreadable medium as claimed in claim 38 wherein the instructions arefurther comprised of directing a controller to implement the enablementstate decision for the load.
 40. The computer readable medium as claimedin claim 37 wherein the enablement state decision is made in accordancewith a schedule, wherein the schedule is comprised of at least oneperiod, wherein the period is comprised of a plurality of segments,wherein the load has an enablement need in order to achieve its dutycycle, wherein the enablement need of the load is defined by a remainingnumber of segments in the period during which the load must be in theload enabled state in order to achieve its duty cycle, and wherein theenablement state decision is constrained by the enablement need of theload.
 41. The computer readable medium as claimed in claim 37 whereineach of the loads in the group of loads has an enablement need in orderto achieve its duty cycle and wherein each of the sets of load statedata from the group of loads is comprised of an energy demand indicationof the energy demand of the load, a duty cycle indication of the dutycycle of the load and an enablement need indication of the enablementneed of the load.
 42. The computer readable medium as claimed in claim41 wherein the enablement state decision is constrained by theenablement need of the load.
 43. The computer readable medium as claimedin claim 41 wherein each of the sets of load state data from the groupof loads is further comprised of a load identifying indicationidentifying the load and a time indication of a time to which the set ofload state data relates.
 44. An apparatus for making an enablement statedecision reflecting an enablement state of an energy consuming load in agroup of energy consuming loads comprising the load and a plurality ofother loads, wherein the enablement state is either a load enabled stateor a load disabled state, the apparatus comprising a processorprogrammed to: (a) generate a set of load state data from the load; (b)compile the set of load state data from the load with sets of load statedata from the other loads; and (c) process the compiled sets of loadstate data in order to make the enablement state decision independentlyof the other loads, wherein the processor is programmed to make theenablement state decision with a goal of achieving a target systemequilibrium for the group of loads, wherein each of the loads in thegroup of loads has an energy demand, wherein each of the loads in thegroup of loads has a duty cycle, and wherein the target systemequilibrium is equal to a sum for all of the loads in the group of loadsof a product of the energy demand of one of the loads and the duty cycleof the one of the loads.
 45. The apparatus as claimed in claim 44wherein the load has an enablement need in order to achieve its dutycycle and wherein the enablement state decision is constrained by theenablement need of the load.
 46. The apparatus as claimed in claim 45wherein the processor is programmed to direct a controller to implementthe enablement state decision for the load.
 47. The apparatus as claimedin claim 44 wherein the enablement state decision is made in accordancewith a schedule, wherein the schedule is comprised of at least oneperiod, wherein the period is comprised of a plurality of segments,wherein the load has an enablement need in order to achieve its dutycycle, wherein the enablement need of the load is defined by a remainingnumber of segments in the period during which the load must be in theload enabled state in order to achieve its duty cycle, and wherein theenablement state decision is constrained by the enablement need of theload.
 48. The apparatus as claimed in claim 44 wherein each of the loadsin the group of loads has an enablement need in order to achieve itsduty cycle and wherein each of the sets of load state data from thegroup of loads is comprised of an energy demand indication of the energydemand of the load, a duty cycle indication of the duty cycle of theload and an enablement need indication of the enablement need of theload.
 49. The apparatus as claimed in claim 48 wherein the enablementstate decision is constrained by the enablement need of the load. 50.The apparatus as claimed in claim 48 wherein each of the sets of loadstate data from the group of loads is further comprised of a loadidentifying indication identifying the load and a time indication of atime to which the set of load state data relates.